Electronic musical instrument with surrounding light sensitive musical effect control

ABSTRACT

An electronic musical instrument comprising a light-sensitive variable resistor whose resistance varies with the intensity of surrounding light and a musical effect control circuit for controlling musical effects such as the volume and color of tones in accordance with the varying resistance of the variable resistor. The musical effect control circuit comprises a variable gain amplifier, tone coloring filter, vibrato oscillator or tremolo oscillator, and the light-sensitive variable resistor is used in the musical effect control circuit to vary, for example, the volume and color of tones, and the speed of vibrato and tremolo according to the condition of surrounding light.

United States Patent 11 1 1111 3,787,602 Okudaira Jan. 22, 1974ELECTRONIC MUSICAL INSTRUMENT WITH SURROUNDING LIGHT SENSITIVE FOREIGNPATENTS OR APPLICATIONS MUSCAL EFFECT CO R 249,391 8/1960 Australia84/DIG. 19 [75] Inventor: Mitsuo Okudaira, Hamamatsu, OTHER PUBLICATI ONS Japan Rufus P. Turner, Photocell Applicatlons, Lafayette RadioElectronics Corporation, Syosset N. Y. pages [73] Assignee: Nippon GakkiSeizo Kabushiki 2 35 3 9 5 Kaisha, Hamamatsu-shi, shiluoka-ken, JapanPrimary ExaminerStephen J. Tomsky 22 F1 d: 0 L 11 1972 AssistantExaminerU. Weldon 1 l e c Attorney, Agent, or Firm-Robert D. Flynn eta1. [21] Appl. No.: 296,597

[57] ABSTRACT [30] Foreign Application Priority Data An electronicmusical instrument comprising a light- Oct. 21, 1971 Japan .Q 46/82876sensitive Variable resistor Whose resistance Varies with the intensityof surrounding light and a musical effect [52 US. Cl 84 1.24, 84/125,84/126, Control circuit for controlling musical effects Such as 4 19 thevolume and color of tones in accordance with the [51] Int. Cl. G10h 1/02Varying resistance of the variable resistor- The musical [58] Field ofSearch 84/1.01, 1.09, 1.13, 1.18, effect control circuit comprises avariable gain p i- 4 2 2 DIG 3 5 fier, tone coloring filter, vibratooscillator or tremolo oscillator, and the light-sensitive variableresistor is [56] References Cited used in the musical effect controlcircuit to vary, for UNITED STATES PATENTS example, the volume and colorof tones, and the speed 3 663 736 5,1972 T 84mm 1 of vibrato and tremoloaccording to the condition of omlsawa 3,558,793 1/1971 Nakada... 84/l.0lsurroundmg hght' 3,514,522 5/1970 M'ussulman 84/DIG. 19 11 Claims, 27Drawing Figures SURROUNDING l8 LIGHT LlGHT 17 SENSITIVE E LE M E N T i 1l2 s TONE TONE FILTERS,

KEYBOARD Pmminm 3.787. 602

' sum 1 or 3 F l G. 1

. 2/ SURROUNDING I 18 LIGHT LIGHT 17\ SENSITIVE ELEMENT i 1 i2 TONE-KEYERS t gmwe+ AMP *CQ GENERATORS V FLTERS l +4 15 KEYBOARDNZ FIG. 2A.3 I FIG. 2B Q TY FREQ I DAR1 FIG.3A FIG. 3B I DA RK FIG.4A g FIG.4B w

7 I DARK FIG .5A FIG.5B W DARK FIG. 6A FIG. 6B 7 DARK F G. 7A F I6. 78Emm PATENTEI] JAN22 I974 SHEET 2 0F 3 -I K- BRIGHT DARK x F I G. 88

F I 6. 8A"

F l G. 05

WHITE LIGHT FIG. 10A

FREQ.

C O G F YELLOW LIGHT FREQ.

FIG.

mmm E T 3 TIME M TISMIII A NE F EL LSE 7 I. G M mm Ema N T OOH TCF B s m2% E II 0 Y B E Y K E K S 1 W 1 T A R E NN OE TG ELECTRONIC MUSICALINSTRUMENT WITH SURROUNDING LIGHT SENSITIVE MUSICAL EFFECT CONTROLBACKGROUND OF THE INVENTION This invention relates to an electronicmusical instrument capable of controlling musical effects according tothe condition of external light in particular.

When playing a musical instrument, a player generally controls thevolume and color of tones at his discretion. Further in a concert hall,the player makes a performance vigorously or gently with his ownintention in view of the environmental condition within said hall.

It is the object of this invention to provide an electronic musicalinstrument capable of automatically varying musical effects such as thevolume and color of tones with the condition of light prevailing in aconcert hall.

SUMMARY OF THE INVENTION An electronic musical instrument generallyincludes an amplifier, tone coloring filter, vibrato oscillator andtremolo oscillator. According to this invention, at least onelight-sensitive variable resistor such as a cadmium sulfide (CdS) cellwhose resistance varies with the intensity of light pevailing, forexample, in a concert hall is used as an element for varying the gain ofan amplifier, the frequency characteristic of a tone coloring filter, orthe oscillation frequency of a vibrato oscillator or tremolo oscillator,thereby controlling musical effects such as the volume and color oftones and the speed of vibrato or tremolo.

The light-sensitive variable resistor may be so designed as to respondonly to predetermined colored lights, using a plurality of opticalfilters, thereby attaining different musical effects according to thevarious colors of surrounding light.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a block diagram of anelectronic musical instrument according to an embodiment of thisinvention which is capable of controlling tone colors according to thecondition of-surrounding light;

FIGS. 2A to 9A present the typical circuits of a plurality oftonecoloring filters usable in FIG. I;

FIGS. 28 to 98 indicate the frequency characteristics of the tonecoloring filters of FIGS. 2A to 9A;

FIG. 10A shows a circuit representing another embodiment of theinvention for controlling the outputs of a plurality of tone coloringfilters having different he quency characteristics according to thecondition of surrounding light;

FIGS. 10B and 10C illustrate the frequency characteristics of thecircuit of FIG. 10A;

FIG. I1 is a block diagram of an electronic musical instrument accordingto still another embodiment of the invention which can control thevolume of tones according to the condition of surrounding light;

FIG. 12A is a circuit diagram of the amplifier of FIG. 11;

FIG. 123 shows the characteristics of the amplifier of FIG. 12A;

FIG. 13A is a circuit diagram of a vibrato oscillator according to afurther embodiment of the invention;

FIG. 1313 shows the characteristics of the vibrato oscillator of FIG.13A;

FIG. 14A illustrates a circuit according to a still further embodimentof the invention for controlling the tremolo effect; and

FIG. 14B illustrates the characteristics of the circuit of FIG. 14A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electronic musicalinstrument of FIG. 1 according to the first embodiment of this inventionincludes, like an ordinary instrument, tone generators ll, keyers I2,keyboard 13, tone coloring filters 14, amplifier 15 and loudspeaker 16.According to the invention, however, there is further provided alight-sensitive element 17 for varying the frequency characteristic ofone or more of the tone coloring filters 14 in accordance with thecondition of light prevailing in an area or concert hall in which thereis placed an electronic musical instrument. The light-sensitive element17 is fitted to that part of the body of an electronic musicalinstrument (not shown) which is convenient for the light-sensitiveelement 17 to receive surrounding light. The lightsensitive element 17may optionally be provided with an optical filter 18 so as to beilluminated only by a pre determined colored light.

The tone coloring filter 14 generally comprises a bandpass filter,high-pass filter or low pass filter. In the electronic musicalinstrument of this invention, the tone coloring filter has its frequencycharacteristic varied by the light-sensitive element 17. To this end,there is used, as shown in FIG. 2A, a light-sensitive variable resistor17 such as a cadmium sulfide cell as an element for defining thefrequency characteristic of the tone coloring filter I4. The frequencycharacteristic of the tone coloring filter of FIG. 2A presents changes,as indicated in FIG. 28, between the bright and dark states ofsurrounding light. The tone coloring filter may be arranged as shown innot only FIG. 2A, but also as in FIGS. 3A and 9A. Further, it ispossible to allow the tone coloring filter to be provided, asillustrated in FIGS. 8A and 9A, with two light-sensitive elementsl7a-l7b and I7c-l7d respectively. The tone coloring filters of FIGS. 3Ato 9A have their frequency characteristics varied as shown in FIGS. 3Bto 98.

When used with an electronic musical instrument, the above-mentionedtone coloring filters have their frequency characteristic controlledaccording to the intensity of light prevailing in the concert hall inwhich the electronic musical instrument is placed. Accordingly, theinstrument can be so constructed that the tones produced in a brightarea have a bright color (namely, includes a great deal of highfrequency component), and the tones given forth in a dark place have adark color (that is, contains a large amount of low frequencycomponent). Therefore, control of illumination in a concert hall enablesthe tones generated therein to be varied in color.

Referring to FIG. 10A, there are provided first and second tone coloringfilters 141 and 143, for example, a flute voice filter and a stringvoice filter which have different frequency characteristics. These tonecoloring filters 141 and 143 are so connected as to receive tone signalsfrom the terminal IN. An output from the first tone coloring filter 141passes through first and second light-sensitive variable resistors 171and 172 connected in series and is conducted to a load 150,

which may be substituted by the input impedance of the amplifier 15. Anoutput from the second tone coloring filter 143 passes through a thirdlight-sensitive variable resistor 173 and resistor 151 and is conductedto said load 150. A fourth light-sensitive variable resistor 174 isconnected to shunt the output terminal'of the second tone coloringfilter 143. Numeral 181 denotes a firstoptical filter substantiallyallowing the passage of only a first colored light, for example, ayellow light and numeral 182 represents a second optical filtersubstantially permitting the passage of only a second colored light, forexample, a blue light. Numerals 183 and 184 show third and fourthoptical filters of the same type as the first and second onesrespectively. Accordingly, the first and third variable resistors I71and 173 respond to the first colored light or yellow light alone, whilethe second and fourth variable resistors 172 and 174 respond to thesecond colored light or blue light alone.

In white light in which both the yellow and blue light components areincluded, all of the above-mentioned variable resistors 171 to 174present a small resistance. Since, in this case, an output from thestring voice filter 143 is shunted by the resistor 174, substantiallyonly an output from the flute voice filter 141 is conducted to the load150. In white light, the circuit of FIG. A has much the same frequencycharacteristics as those of the flute voice filter 141 as illustrated inFIG. 10B. But in blue light, the light-sensitive resistor 171 exhibits ahigh resistance thereby blocking a flute voice signal, and thelight-sensitive resistor 174 exhibits a low resistance thereby shuntinga string voice signal. Consequently, neither voice can be heard.

In yellow light, however, the resistors 171 and 173 have smallresistance, whereas the resistors 172 and 174 present increasedresistance. In this case, the division ratio for an output from theflute voice filter. 141 defined by the resistor 172 and load 150 has asmaller value than the division ratio for an output from the stringvoice filter 143 determined by the resistor 151 and load 150.Accordingly, the load 150 is mainly supplied with an output from thestring voice filter 143. Thus in yellow light, the circuit of FIG. 10Ahas substantially the same frequency characteristic as that of thestring voice filter 143 as shown in FIG. 10C. Where there is used thecircuit of FIG. 10A, there can be obtained a tone color corresponding tothe changed color of illumination.

FIG. 11 represents an embodiment of this invention capable ofcontrolling tone volumes according to the intensity of illumination. Inthis case the light-sensitive element 17 is used to vary the gain of theamplifier 15.

FIG. 12A illustrates a manner in which the lightsensitive variableresistor 17 is coupled with the amplifier. 15 to vary its gain. Whilecoupling may be effected by various methods, the variable resistor 17 ofFIG. 12A is used to control the level of A.C. signals supplied to theamplifier 15, thereby varying its gain with respect to the A.C. signals.FIG. 1213 shows the characteristic of the amplifier gain with respect tothe intensity of light.

FIG. 13A represents another embodiment of this invention where thelight-sensitive variable resistor 17 is used to determine the frequencyof a vibrato oscillator. An output from the vibrato oscillator isconducted to the tone generator 11 to impart a vibrato effect bysubjecting tone signals to frequency modulation using the known process.Namely, the vibrato speed is controlled, as shown in FIG. 13B, accordingto the intensity of light.

FIG. 14A indicates a further embodiment of this invention where thereare used first and second lightsensitive variable resistors and 176 in atremolo effect producing circuit. The first resistor 175 is used tocontrol the tremolo speed as an element for determining the frequency ofa tremolo oscillator such as an astable multivibrator. The secondresistor 176 is connected to the output of the tremolo oscillator tocontrol the level of output signals therefrom, namely, the tremolodepth. To impart a tremolo effect to tone signals, there may be used afield effect transistor 177 receiving a tone signal input from a tonegenerator or keyer as shown in FIG. 14A. The first and second variableresistors 175 and 176 may be so designed as to be controlled bydifferent colored lights. The speed and depth of the tremolo varies withthe intensity of light as illustrated in FIG. 143.

In the foregoing embodiments, there were used a light-sensitive variableresistor such as a cadmium sulfide (CdS) cell. However, it is possibleto use other photoelectric conversion elements such as aphototransistor.

What is claimed is:

1. In an electronic musical instrument comprising a source of tonesignals coupled through a keyer to a musical effect control means whichincludes at least one of an amplifier circuit, a tone coloring filtercircuit, and a tremelo oscillator circuit coupled in the path of saidtone signals to control said tone signals to create musical effects, avibrato oscillator circuit connected to said source of tone signals, andsound producing means coupled to said musical effect control means, anambient light detecting means located to receive surround? ing lightfrom the area in which said instrument is located, said ambient lightdetecting means comprising at least one light-sensitive element havingalight variable characteristic and arranged to receive said surroundinglight from the area in which said instrument is located, said at leastone light sensitive element being connected within the circuit of atleast one of said amplifier, tone color filter, vibrato oscillator, andtremelo oscillator to control the musical effects in accordance with thecharacteristic of said light-sensitive element which varies responsiveto the condition of said surrounding light.

2. The electronic musical instrument according to claim I wherein saidmusical effect control means includes a tone coloring filter, andwherein said at least one light-sensitive element comprises alight-sensitive variable resistor coupled to said tone coloring filterfor defining the frequency characteristic of said tone coloring filter.

3. The electronic musical instrument according to claim 1 wherein saidmusical effect control means includes a tone signal amplifier andwherein said at least one light-sensitive element includes alight-sensitive variable resistor coupled to said amplifier to vary itsgain with respect to tone signals.

4. The electronic musical instrument according to claim I wherein saidvibrato oscillator imparts a vibrato effect to tone signals and whereinsaid at least one lightsensitive element comprises a light-sensitivevariable resistor coupled to said vibrato oscillator to determine theoscillation frequency of said vibrato oscillator.

5. The electronic musical instrument according to claim 1 wherein saidmusical effect control means includes a tremolo oscillator adapted toimpart a tremolo effect to tone signals, and wherein said at least onelight-sensitive element includes comprises a lightsensitive variableresistor coupled to said tremolo oscillator to determine the oscillationfrequency of said tremolo oscillator.

6. The electronic musical instrument according to claim 1 wherein saidmusical effect control circuit includes a tremolo effect to tonesignals, and wherein said at least one light-sensitive element comprisesa light-sensitive variable resistor coupled to said tremolo oscillatorto control the level of an output from said tremolo oscillator.

7. The electronic musical instrument according to claim 12 wherein saidambient light detecting means includes an optical filter permeable onlyto a predetermined colored light and located in the light path to saidlight-sensitive element.

8. The electronic musical instrument according to claim 1 wherein saidat least one light-sensitive element is a cadmium sulfide cell.

9. An electronic musical instrument comprising:

a source of tone signals;

at least first and second tone coloring filters connected througha'keyer to receive the tone signals from said source, said tone filtershaving different frequency characteristics;

an ambient light detecting means connected to receive surrounding lightfrom the area in which the instrument is located, said ambient lightdetecting means being responsive to first and second surrounding coloredlights and comprising light sensitive means coupled to the outputs ofsaid first and second tone coloring filters so as to allow the passageof an output from said first tone coloring filter in response to saidfirst surrounding colored light, but to substantially prevent thepassage of an output from said second tone coloring filter for saidfirst surrounding colored light, and to allow the passage of an outputfrom said second tone coloring filter in response to said secondsurrounding colored light, but to substantially prevent the passage ofan output from said first tone coloring filter for said secondsurrounding colored light, and

sound producing means coupled to the outputs of said tone coloringfilters.

10. The electronic musical instrument according to claim 9 wherein saidambient light detecting means comprises: first and secondlight-sensitive variable resistors connected in series with the outputof said first tone coloring filter, said first and second variableresistors being adapted to rspond to said first and second coloredlights respectively; a third light-sensitive variable resistor connectedin series with the output of said second tone coloring filter; and afourth light-sensitive variable resistor connected to shunt the outputof said second tone coloring filter, said third and fourth variableresistors being adapted to respond to said first and second coloredlights respectively.

11. The electronic musical instrument according to claim 10 wherein saidambient light detecting means further comprises: at least one firstoptical filter in the light path of said first and third variableresistors for allowing the passage of only said first colored light tosaid first and third variable resistors; and at least one second opticalfilter in the light path of said second and fourth variable resistorsfor allowing the passage of only said second colored light to saidsecond and fourth variable resistors.

1. In an electronic musical instrument comprising a source of tonesignals coupled through a keyer to a musical effect control means whichincludes at least one of an amplifier circuit, a tone coloring filtercircuit, and a tremelo oscillator circuit coupled in the path of saidtone signals to control said tone signals to create musical effects, avibrato oscillator circuit connected to said source of tone signals, andsound producing means coupled to said musical effect control means, anambient light detecting means located to receive surrounding light fromthe area in which said instrument is located, said ambient lightdetecting means comprising at least one light-sensitive element having alight variable characteristic and arranged to receive said surroundinglight from the area in which said instrument is located, said at leastone light sensitive element being connected within the circuit of atleast one of said amplifier, tone color filter, vibrato oscillator, andtremelo oscillator to control the musical effects in accordance with thecharacteristic of said lightsensitive element which varies responsive tothe condition of said surrounding light.
 2. The electronic musicalinstrument according to claim 1 wherein said musical effect controlmeans includes a tone coloring filter, and wherein said at least onelight-sensitive element comprises a light-sensitive variable resistorcoupled to said tone coloring filter for defining the frequencycharacteristic of said tone coloring filter.
 3. The electronic musicalinstrument according to claim 1 wherein said musical effect controlmeans includes a tone signal amplifier and wherein said at least onelight-sensitive element includes a light-sensitive variable resistorcoupled to said amplifier to vary its gain with respect to tone signals.4. The electronic musical instrument according to claim 1 wherein saidvibrato oscillator imparts a vibrato effect to tone signals and whereinsaid at least one light-sensitive element comprises a light-sensitivevariable resistor coupled to said vibrato oscillator to determine theoscillation frequency of said vibrato oscillator.
 5. The electronicmusical instrument according to claim 1 wherein said musical effectcontrol means includes a tremolo oscillator adapted to impart a tremoloeffect to tone signals, and wherein said at least one light-sensitiveelement includes comprises a light-sensitive variable resistor coupledto said tremolo oscillator to determine the oscillation frequency ofsaid tremolo oscillator.
 6. The electronic musical instrument accordingto claim 1 wherein said musical effect control circuit includes atremolo effect to tone signals, and wherein said at least onelight-sensitive element comprises a light-sensitive variable resistorcoupled to said tremolo oscillator to control the level of an outputfrom said tremolo oscillator.
 7. The electronic musical instrumentaccording to claim 12 wherein said ambient light detecting meansincludes an optical filter permeable only to a predetermined coloredlight and located in the light path to said light-sensitive element. 8.The electronic musical instrument according to claim 1 wherein said atleast one light-sensitive element is a cadmium sulfide cell.
 9. Anelectronic musical instrument comprising: a source of toNe signals; atleast first and second tone coloring filters connected through a keyerto receive the tone signals from said source, said tone filters havingdifferent frequency characteristics; an ambient light detecting meansconnected to receive surrounding light from the area in which theinstrument is located, said ambient light detecting means beingresponsive to first and second surrounding colored lights and comprisinglight sensitive means coupled to the outputs of said first and secondtone coloring filters so as to allow the passage of an output from saidfirst tone coloring filter in response to said first surrounding coloredlight, but to substantially prevent the passage of an output from saidsecond tone coloring filter for said first surrounding colored light,and to allow the passage of an output from said second tone coloringfilter in response to said second surrounding colored light, but tosubstantially prevent the passage of an output from said first tonecoloring filter for said second surrounding colored light, and soundproducing means coupled to the outputs of said tone coloring filters.10. The electronic musical instrument according to claim 9 wherein saidambient light detecting means comprises: first and secondlight-sensitive variable resistors connected in series with the outputof said first tone coloring filter, said first and second variableresistors being adapted to rspond to said first and second coloredlights respectively; a third light-sensitive variable resistor connectedin series with the output of said second tone coloring filter; and afourth light-sensitive variable resistor connected to shunt the outputof said second tone coloring filter, said third and fourth variableresistors being adapted to respond to said first and second coloredlights respectively.
 11. The electronic musical instrument according toclaim 10 wherein said ambient light detecting means further comprises:at least one first optical filter in the light path of said first andthird variable resistors for allowing the passage of only said firstcolored light to said first and third variable resistors; and at leastone second optical filter in the light path of said second and fourthvariable resistors for allowing the passage of only said second coloredlight to said second and fourth variable resistors.